September 10, 2012

Instructables user bennelson shows us how you can make a Smart Grid using an old UPS. This allows him to charge his 48 volt electric motorcycle using a discarded UPS. When the power fails he can also backfeed his garage or house using his UPS system which would then draw current from the motorcycle battery to generate AC power. He unplugs the UPS AC power from the wall, connects a male to male AC adapter to feed UPS created AC power from the back of the UPS into a special wall outlet, not sure why he isn’t just using what seems to be a dedicated UPS power plug. The main breaker of the garage sub-panel is turned off to isolate the garage panel from the outside world, the breaker that is now being fed power by the UPS is turned on and now is providing power on whatever leg is it tied into.

Great idea, nice to see this equipment being used to charge the electric motorcycle batteries. But I think the limit of the system should have ended there. In my opinion just having the outlets at the rear of the machine would have been enough, possibly even leaving a trouble light plugged in for use when the power fails would be a bonus. I don’t think this should be duplicated since there are too many things that can go wrong. I would hate to see a hydro worker get shocked while restoring power on the pole because the main breaker was forgot in the on position.

2 Responses to “Smart Grid using an old UPS”

This is neat. I did something like this with an old APC unit. It was given to me with dead batteries so using the Anderson pole connection on the back for external banks, i wired up some deep cycle wheel chair batteries and it has about 4x the run time. According to the manual, it would accept 10 external banks daisy chained together. I think the OEM battery packs were 14 Ah, so i could technically hook up 140ah worth of deep cycle batteries and be able to keep up and running for a good long time.